AUTHOR=Alves Rúbens Prince dos Santos , Andreata-Santos Robert , de Freitas Carla Longo , Pereira Lennon Ramos , Fabris-Maeda Denicar Lina Nascimento , Rodrigues-Jesus Mônica Josiane , Pereira Samuel Santos , Carvalho Alexia Adrianne Venceslau Brito , Sales Natiely Silva , Peron Jean Pierre Schatzmann , Amorim Jaime Henrique , Ferreira Luís Carlos de Souza TITLE=Protective Immunity to Dengue Virus Induced by DNA Vaccines Encoding Nonstructural Proteins in a Lethal Challenge Immunocompetent Mouse Model JOURNAL=Frontiers in Medical Technology VOLUME=2 YEAR=2020 URL=https://www.frontiersin.org/journals/medical-technology/articles/10.3389/fmedt.2020.558984 DOI=10.3389/fmedt.2020.558984 ISSN=2673-3129 ABSTRACT=

Dengue virus represents the main arbovirus affecting humans, but there are no effective drugs or available worldwide licensed vaccine formulations capable of conferring full protection against the infection. Experimental studies and results generated after the release of the licensed anti-DENV vaccine demonstrated that induction of high-titer neutralizing antibodies does not represent the sole protection correlate and that, indeed, T cell-based immune responses plays a relevant role in the establishment of an immune protective state. In this context, this study aimed to further demonstrate protective features of immune responses elicited in immunocompetent C57BL/6 mice immunized with three plasmids encoding DENV2 nonstructural proteins (NS1, NS3, and NS5), which were subsequently challenged with a DENV2 strain naturally capable of inducing lethal encephalitis in immunocompetent mouse strains. The animals were immunized intramuscularly with the DNA vaccine mix and complete protection was observed among vaccinated mice. Vaccine induced protection correlated with the cytokine profiles expressed by spleen cells and brain-infiltrating mononuclear cells. The results confirm the pivotal role of cellular immune responses targeting nonstructural DENV proteins and validate the experimental model based on a DENV2 strain capable of infecting and killing immunocompetent mice as a tool for the evaluation of protective immunity induced by anti-DENV vaccines.